Stable P-Type chemical doping of graphene with reduced contact resistance by a single layer PFSA.

Recently, graphene has provided unprecedent progress in device performance at the atom limit. High performance of field-effect transistors (FETs) requires a low graphene-metal contact resistance. However, the chemical doping methods used to tailor or improve the properties of graphene are sensitive to ambient conditions. Here, we fabricate a single layer perfluorinated polymeric sulfonic acid (PFSA), also known as Nafion, between graphene and the substrate as a p-type dopant. The PFSA doping method, without inducing any additional structural defects, reduces the contact resistance of graphene by ~28.8%, which has a significant impact on practical applications. This reduction can keep at least 67 days due to the extreme stability of PFSA. Effective, uniform and stable, the PFSA doping method provides an efficient way to reduce the contact resistance of graphene applications.